Dimensional Principles of IPC-7351B
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Category: PCB Footprint Expert
Forum Name: Questions & Answers
Forum Description: issues and technical support
URL: https://www.PCBLibraries.com/forum/forum_posts.asp?TID=1744
Printed Date: 18 Nov 2024 at 6:38pm
Topic: Dimensional Principles of IPC-7351B
Posted By: drj-bbe
Subject: Dimensional Principles of IPC-7351B
Date Posted: 04 Aug 2015 at 1:25am
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Hello Tom, There is a dimension "Amax" indicated in below principles of IPC-7351B, see below picture. But it seems there is no drawing to define which size is for "Amax". Could you please help on this question? Thanks
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Replies:
Posted By: Tom H
Date Posted: 04 Aug 2015 at 6:08am
This condition creates a Outward L lead -  This lead style has a different calculation then the normal Gull Wing lead style:  ------------- Stay connected - follow us! https://twitter.com/PCBLibraries" rel="nofollow - X - http://www.linkedin.com/company/pcb-libraries-inc-/" rel="nofollow - LinkedIn |
Posted By: drj-bbe
Date Posted: 04 Aug 2015 at 6:38pm
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I have mark Amax and Smin below, is it correct?  |
Posted By: Tom H
Date Posted: 04 Aug 2015 at 7:52pm
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Please download the SMD Reference Calculator. All values and dimensional assignments are displayed. You can change the calculation values and observe the resulting land pattern results. Download here - http://www.pcblibraries.com/forum/ipc7351-smd-pth-reference-calculators_topic785.html" rel="nofollow - http://www.pcblibraries.com/forum/ipc7351-smd-pth-reference-calculators_topic785.html ------------- Stay connected - follow us! https://twitter.com/PCBLibraries" rel="nofollow - X - http://www.linkedin.com/company/pcb-libraries-inc-/" rel="nofollow - LinkedIn |
Posted By: drj-bbe
Date Posted: 04 Aug 2015 at 8:11pm
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I cann't find dimension "A" mentioned above in SMD reference calculator. It seems only for chip component.
Could you tell me which size is for the dimension "A" ?
Thanks.
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Posted By: Tom H
Date Posted: 05 Aug 2015 at 8:27pm
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Sorry for the late reply especially for such a simple question, it's been really busy lately. Amax = the Lead Span  3D model created by Library Expert. ------------- Stay connected - follow us! https://twitter.com/PCBLibraries" rel="nofollow - X - http://www.linkedin.com/company/pcb-libraries-inc-/" rel="nofollow - LinkedIn |
Posted By: Tom H
Date Posted: 05 Aug 2015 at 8:57pm
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This picture illustrates what the IPC-7351B text condition for Gull Wing lead is referring to. When the Terminal Leads bend inward.  ------------- Stay connected - follow us! https://twitter.com/PCBLibraries" rel="nofollow - X - http://www.linkedin.com/company/pcb-libraries-inc-/" rel="nofollow - LinkedIn |